SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c2da1a6ad18217febf06c2e7649d737084a3d31ca0639acc9db6de0fd4dbdd1' 
  AND token = 'P1ZjjKofwD9xx4qGwX2vTA9eFTiOu/4gRqxtTAN4MGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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