SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cad582e87c8eeb113711804d0eb98c4e94994c7361adbb5621d4501608e8097' 
  AND token = '/bOWkfQqpTXdFVjfW3RY/gnZdtneBpSKETyWUnstLJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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