SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'abc758db2de8541d8bb8931cd368a2314a11195f8c54f718c9cfd28776f5a304' 
  AND token = 'r7EWJiibHJRr3TXeJKC0uUqA+4gUN25RuZMBVBWMsnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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