SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99f37b341031118604bf83645420212753e7fb33d9d31c9343e859b19232a31d' 
  AND token = 'NCfvtpCCvurl+WKF90z/wX2yfIZe3DzkbeD7/PVigsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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