SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '305bd1dc3a2d774a3272bedaf77114c29d1c8e684967442558366a14bdeb1a26' 
  AND token = 'oUXBrxN32hKq7k8iv1RncbrGizW7XNSovtqv8Hsf7pI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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