SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1760bdfe2851777e6122cac112235c84cbfc4f450dcdd1316562f0e2dd59f50f' 
  AND token = 'MGj0J7dDdMoyu8XFQNquMaFsOSm4Z8KRHnm9lUtYZ+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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