SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afccbef13fb2d2d6d67a291f861d9adc1196e7318c67f15d2e1fe92ae7f6918e' 
  AND token = 'pQeybZFTYDyhrk9N3qjjWO0ZCL6Jsxgd7jsipsw+Zmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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