SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e191dd7477cbc4513eda6f459aae962ae5e34a49934648c106e33e346baba36a' 
  AND token = 'FjgygWpvYLDRwR9roCTlsdqXAjLAtF0tj+f24OLtDhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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