SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72806270775218572f227ed48494dffb688e5b58a066b04b90efa53c5f64dfd0' 
  AND token = '8RDKbPkx0VGWWYs27hvYvfNdhtZB5WMB1VNEXFj/h0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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