SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7042bd9ebd807da1e454357eda11cb3a066192caf2219632829d1ab5d94b73d' 
  AND token = 'uRjYXpghYLJDntBcLVX+VXNb7cmN9am8VLZWooPmX/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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