SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66d88afc1fcd08fd900d845ca597fedb084c35a32ec4ac4be3f6e042ee75ee2' 
  AND token = 'rgN+ZCL47BBA9tZLhTtIA2PylitsDE62Xxxa8EnyotA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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