SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433f8b515434a13de033e07bd1928e9521e52833fb190d900e811c4b1e575d5f' 
  AND token = 'fPJUqmLsZi3hzJB6/7RYYRFFnakVd4wMUj1wDsQpfAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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