SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4a5ef281bb65c9b20b0171284842eb7f4aa4291b1439372ad7c76431aaab075' 
  AND token = '0EqrWpQ2GEUKEkHb/THcBLIwuZDV77fDW+qP6qcOESs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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