SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4382f7182b131ef53c4375cc796f468c6238a277f96016aeac96c344ccffffcb' 
  AND token = 'JuUVoDml5vblutGdCM8stoZUTLRajny4asQBMHtB0OI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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