SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8627f470933411b30d5f103dbf8d02274cfdbc87dc0ea4c19cc719f4b9d36831' 
  AND token = 'X1OLjtNraLiw44NzJKpChnITn1n6ENAoZqVDjqLaA9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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