SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abdb23c8d63c13abc43611f9043918d2a7231441714edc5aefeff63580bbeec3' 
  AND token = 'cc20/ESADc9n4fKCBL31Y3qFBdVmBPEYbPuM8POVhNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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