SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dfdf53d27355c100016c90f17df6729bcc5f3feaf50c94e4101b71874ae3fc1' 
  AND token = 'yGM2sAJWei3cjRpxz51SXFpgpywb2sAMecLEwu+QDRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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