SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fffcf6a1676cbd898750d0d419f75979d536c81fbf2b1cd6611f7d5bc540e9b6' 
  AND token = 'GMrczg/IMoCjGQQ9LTYWgS8dfcX/wPL/FyDWJLJst0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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