SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '318df1d4f915f35ff07f6dffcfa275e477ffc9ae78c8338fa278f46aee454ae5' 
  AND token = '0snHeiaLG/yHrSIcGeXRggqT9XXqwmRUduZL2ncfWZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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