SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b042c03ec2fd1cd37f74287218290de839e547702acd2d09d1df0daf52f092f' 
  AND token = 'Mjcf6PcXMzV63FX9u9fxfyUJlClTxqRTYH345U9j4Sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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