SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5fc30dfa0b62854727ed5437bd859588bb6a5095e9735bb32ba43a8dd742ba2' 
  AND token = 'E49R+YmipSquRwLdv5zvLtR2l8tNzerEqSwlh8iIsBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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