SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41aa86ef7f120bc40a2e999fe2b5a71aab7a5ae7409a64e3fc8fcacc670dfe75' 
  AND token = 'Ty5f2Twvo7gEkQUVwuqJgaAsYwtcyzWblBDIWUGjCJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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