SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61454fefe2e29da073257818b765acd11cffbaea67a9088b89ea9d9d209abc55' 
  AND token = 'c3aK5k0SXgB3hBNmcLxdv/InpeL6xrDFvskad5Yl6rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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