SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a31446c20c2cb22aabb22274266849dd70ca83146eb7f09a6297bd568d86808' 
  AND token = '2Uylxy6RAeTZMTLjV03mbPeXJsES8aa09uA2ZftU8i0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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