SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ec411adda3c79019449d7819592edd9e2b3619d018d3264c2e3e5d9a719ee4a' 
  AND token = 'YmPa4fjiYXKM54KXf0dqjzSP9LRwc+alwabfpkLBiBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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