SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0b31cc6a1d7240bd93ca7d036c41c64f7dd13616594089aeef4660cd8dc3db50' 
  AND token = 'veNcoKpIaTA5cbztVvFC64gnvuFeLlVMQ6LZdAZnz9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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