SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f59e18ead712d496f5fe06845b077e54a2d21444ad36c59f411997cb36010f9a' 
  AND token = 'etxxQbpK3OLcnueZo1yLwGFEp0APjbneoNWJAYZ6o14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}