SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea0d12fa715bb1f4894cb9125ae0b1f2317fc09e7c5616d97cf50f56713c5136' 
  AND token = 'yvpEFQw5Baaf5R3kA7yoVbTRhe4S3uXE/uoOsCpL6U4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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