SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac745ef3d9032b0938b5e93f1356ad2fbc0f7d4d1ec5576e1af757fc1f4d901' 
  AND token = 'oBfQwQ71jJwG2ZPtanHRNCluKJd/bZCRC5m2hfiQsjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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