SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6c646714e682d4cf6fb3d838ecaaa9d4223bb6422fe2accb053b1542e70d31b' 
  AND token = 'XNBAkIFBQv+msZ8Y3Cw0+OfxSbYBmAslrtQmc4G1azI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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