SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f590f8028d4f9bb4d823f420ea9f0c4467a56c5c21b449d1b1db63fb2d1da9f' 
  AND token = 'SVCwE9PnS5YhfvnJpErEcCV23Z1JCGYr9L6zTJ9efSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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