SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47733551ff4eefdbcf944401187d8bace69b554829dc17fc033f7c5d8b6860bd' 
  AND token = 'EQNyQvKy/sfUk61ZMfhv8TsoB9nt1nBubT/EtdJJ+cg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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