SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '484b8606717f8a776ace4782d58bf3248a36f6b939a8f1810bb025b93e75ebce' 
  AND token = 'lmBba0/I4Hyh/ILQpT4j/LlXU0Ts7esjze/fcY3LUbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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