SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c3716ff468b422593d6d70e02ff80df5f64290387a38f8a47ea7f6a7ab2da6db' 
  AND token = 'O4890h5EDxDr+bQw7n/eUQMz9oJs8Co0YijLb+ICB/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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