SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f163b95bd7b547fc26842d71e165fc12d44033e1b7ff1b80314d3162fabff97f' 
  AND token = '14gI/RJS8K+8n9ELYWq3mVR+OWcSv79ZDlUEKi0cuHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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