SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd87c07bedb7ef7fcda7407dfceda26fa525128580f197631df0fc1b2ef6220f2' 
  AND token = 's6KSgWFiAn99fVnD324GErUhbqnz9qs8CiXP7o4Tip8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}