SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f85215c711539147daa0ccfec0c76edb8eb1bd8e22be830d6b3343a7e4af0d9' 
  AND token = 'nQgcXN2SKBIBVnXhbbOXpfo+kxgxVk4duRInDGrhtRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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