SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a1956a5b9db2edad1dde6e3fab2c5031549cf5ac9adeafa789224aa59d179a6' 
  AND token = 'c36s3zAuLfA38xxwk9gMQ7wKRyPjBVH25medFofFM8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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