SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3881c076f240b852c321c335ca1c2aa45d56be16b3d770f51d9327288e98c1cf' 
  AND token = '98gHLGGpDTOxZXPHIhlmtmWLQjgR5Pbo+QutBb5kJhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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