SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acc31c563cf3e171188807d1d7edd3c15041f87aa6c28e018ed022c781a2c329' 
  AND token = '2WOHBLdGYEdPDmDiJwg8Q7u1h1JcU3YvUV/U7oSXEu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}