SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74004f6289641322a94bd246cb856ba9866b5e8b950b70abe1fa3951d71d7d92' 
  AND token = 'CgRyheZNw6qH8Kh87VzmhASZi+QDgsxrgQe4n12wzwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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