SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43cc75b18b8cbda85ee0cdf79fba467fd659c4f92d5b4d2346832c47487d8f1a' 
  AND token = '98Bc5uRbw+0I+ATBwLQNWX/PM0H+fmNAuxKVIIo2Jm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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