SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3be717a777dde1e4cfa31ad68b7f475d004a7527309edf70612298deb4a294d3' 
  AND token = '0tgeVm1DbLQo1XeOrKaCma7QeJ3H5FF6MEaS0UOzu5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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