SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '755ce8975b977219d834fbb2b5fe4a64b37c2b09a66d94d7e96b62024846e717' 
  AND token = 'Xmbg9YYuvW7pMDaqh+wKjCufVmKBFJjF4TnM1HPTpL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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