SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0d4878a1e2effb990627334271ef030e39f7f040c936fa23499f3d3aa6ece1ed' 
  AND token = '+/kCqsIGxl0JYlP658ThgNsWbaUQKseyYWmvvkjahJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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