SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f11f8d82581a4aa2c49475a93260c6e8c58d70a361925bee5752bb43bb08f694' 
  AND token = '0dGg34lJWXH/Vjlsy2OQA+GwfnJBU2wO4/WIiBEea0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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