SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b4d46898cc4cd7e56b4e6e37160a3aab0db00b2987633332b358669e01c7e46' 
  AND token = '/3DfUOlGEFVKHNZoklhtdpjXSmYuw5cKaqAkU6RFsSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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