SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c0c19a2475361cc7cbde88ff29119f4123d8b44cf935870c57bd13cc4c26271' 
  AND token = 'eaXGywD9oHqhuB9/qY7XWKeGaF1GQnLpjUyqkfTCVJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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