SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '248ca1692f054695599fb6c2c3890b42742cc0a1443415fbcd4ad7335252b968' 
  AND token = 'I5Ir92g39VJVCGzqsQm6qMFzDNK2mhHgF4OauXiOs4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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