SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79416b76a3a7f18a8825f8bb553a442a31643d33a874b537ed462aba0ae0e193' 
  AND token = 'T4R7QFACcJqX200+htPDYgSiS6aMTlSRw9wCToWaXRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}