SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a93abe9c79dd04283e05b4bf9957a27b19d6aae6befc980e5a19d4f63e83544c' 
  AND token = 'KfT6fbqnYMVC71sCzXuNgxYF5el+JfZOhgpGlUBel68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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