SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f0aed5f6426e68114cf4354bb464c1c1fc68e54b604fbe7a3742e7f0c7948ea6' 
  AND token = 'RWZ/tCBhKVEYSl4H7FEVp9k7MlYEzovcg8QXsEZx2DA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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