SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd63d6fdc067d80a8aaa44b0751b6e290188ad5ee02df0d7913cb13aa2e82dd0a' 
  AND token = 'Ed8CUVrp3s4ulxnRv9kGdiemaaSglgZTCXcCIJ0k8b4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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