SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03b387dfdcb9e30931da5c21b99f2e2ba13c44fea2713db26e497e33c0b9544c' 
  AND token = 'Y9tw7sAjSDYeCe701mfIL82Z2IaPsbHpWJhue7RfWao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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