SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50f994b54ccf19cef5c46369e23f1b2259a6fedb1ae24d18eeab660129772cb6' 
  AND token = 'ZFVQBqFwtXZI5vb9adVCdcumkEoFQG7i54SsAQsv8ZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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