SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c0af04548d82395f43623590089525701707240ca4fbcec081c70f9986c4878' 
  AND token = '8LOjm1oxBY5PhYAQgPz/OdhnbW9dsv6U1Pui32rlgpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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