SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0741c4ffdf79d4b6301a926f483f902836426578489781242c8033e944a49de3' 
  AND token = 'BKqkSN5A5AYPUtINUjgM2bJFYmV8hqvEJ/AL2L7yzBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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