SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bfd7e0845ebf716b884ff467c2c91549a49f9f88d42d0cc1330a5f27c8f98018' 
  AND token = 'lmUGz1LS9JYmbGF2O1Ixp7kinYME2YVwqZPX/ko8D2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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