SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba9c03d7c8dbc52be221eba74d5764bfb86f426a80ed2ef4e565cbebc5e68e8f' 
  AND token = 'kk5Ua+dU4x4icghKPvlPNhLk+abUzcTo+xOsLRa3oic=' 
  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"
    }
  }
}