SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '821fbb0941b488f60f782552157cf94dfa3074c90c66c4ab97779e65cf0806f8' 
  AND token = 'nJJBsvjMl3TNNzfvx2eyhZeGzc/cAD41j+vq3CzRglQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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