SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb60dbbbad9f508442eb25296a4e7d2518733ce076b9c0dfe862003677ef293f' 
  AND token = 'lVs2SrxvGKhCIlG9AvCj7BFqiNUgU4Y5Q95KeCegX8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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